This study was designed to determine if the K-Complex reflects an arousal from sleep or a sleep protection mechanism. Ten participants were presented auditory stimuli every 20 s while asleep. Trials were sorted according to the presence or absence of a K-Complex. A fast Fourier Transformation of the data was computed on EEG segments prior to and following stimulus onset. The log power of activi...

Although a slowing of electroencephalographic (EEG) activity during wakefulness and -to some extent- sleep of Alzheimer disease (AD) patients (i.e., increased slow-frequency activity) was documented, recent findings in healthy elderly show a decreased 0.6-1 Hz slow wave activity (SWA) during NREM, which was associated to β-amyloid deposition and impaired hippocampal memory consolidation. We hyp...

generators. Our goal is to make this description more concrete. Note that G(k, n) = U(n)/(U(k)×U(n− k)) = St(k, n)/U(k) is the quotient by U(k) of the complex Stiefel manifold St(k, n) of partial orthonormal k-frames in C. Thus any finite-dimensional representation ρ : U(k) −→ GL(W ) of U(k) gives rise to the natural vector bundle St(k, n)×ρ W −→ G(k, n), where St(k, n) −→ G(k, n) is viewed as ...

Let V be a finite dimensional complex vector space and W ⊆ GL(V ) be a finite complex reflection group. Let V reg be the complement in V of the reflecting hyperplanes. We prove that V reg is a K(π, 1) space. This was predicted by a classical conjecture, originally stated by Brieskorn for complexified real reflection groups. The complexified real case follows from a theorem of Deligne and, after...

Marion Usselman is Associate Director for Federal Outreach and Research for Georgia Tech’s Center for Education Integrating Science, Mathematics and Computing (CEISMC). She has been with CEISMC since 1996 developing and managing university-K-12 educational partnership programs and assisting Georgia Tech faculty in creating K-12 educational outreach initiatives. Before coming to CEISMC, Marion e...

Vitamin K is a cofactor in the -glutamyl carboxylation pathway, a posttranslational conversion of specific glutamate residues into -carboxyglutamic acid (Gla) residues, catalyzed by the endoplasmic reticulum enzyme -glutamyl carboxylase. The substrates of carboxylase are the so-called vitamin K–dependent proteins, which are involved in diverse physiological processes such as blood coagulation, ...

Let Π (k) (n−1)k+1 be the poset of partitions of {1, 2, . . . , (n − 1)k + 1} with block sizes congruent to 1 modulo k. We prove that the order complex ∆(Π (k) (n−1)k+1 ) is a subdivision of the complex of k-trees T k n , thereby answering a question posed by Feichtner [F, 5.2]. The result is obtained by an ad-hoc generalization of concepts from the theory of nested set complexes to non-lattices.

Almost all alkali feldspar crystals contain a rich inventory of exsolution, twin, and domain microtextures that form subsequent to crystal growth and provide a record of the thermal history of the crystal and often of its involvement in replacement reactions, sometimes multiple. Microtextures strongly influence the subsequent behavior of feldspars at low temperatures during diagenesis and weath...

We introduce a new family of subdivision schemes called jet subdivision schemes. Jet subdivision schemes are a natural generalization of the commonly used subdivision schemes for free-form surface modeling. In an order r jet subdivision scheme, rth order Taylor expansions, or r-jets, of functions are the essential objects being generated in a coarse-to-fine fashion. Standard subdivision surface...